This invention relates to the art of pressure relief valves and more particularly to an indicator which signals when a pressure relief valve has operated.
In transformers or voltage regulators which utilize a pressure relief device to limit maximum internal pressure, such equipment is normally unattended. Since the relief valves on such equipment generally automatically reset after excessive internal pressure is relieved, there is no way to warn that a predetermined maximum internal pressure has occurred.
The device of the present invention will indicate when the relief valve has operated, thus providing a means to warn maintenance personnel when corrective action is to be taken to avoid damage to an expensive transformer or voltage regulator.
An object of this invention is to provide a means to warn the internal pressure of an enclosure has exceeded a predetermined value.
Another object is to provide a means for use in indicating when a pressure relief valve has operated, even if the pressure relief valve automatically returns to operational condition.
Still another object is to provide a pressure relief operation indicator device which is of simple structure, reliable in operation, and which can be easily rest for use as often as required.